Research on the bioavailability of water from thickened fluids has recently been published and it concluded that the addition of certain thickening agents (namely, modified maize starch, guar gum, and xanthan gum) does not significantly alter the absorption of water from the healthy, mature human gut. Using xanthan gum as an example, our ‘‘proof of concept’’ study describes a simple, accurate, and noninvasive alternative to the methodology used in that first study, and involves the measurement and comparison of the dilution space ratios of the isotopes 2H and 18O and subsequent calculation of total body water. Our method involves the ingestion of a thickening agent labeled with 2H 1 day after ingestion of 18O. Analyses are based on the isotopic enrichment of urine samples collected prior to the administration of each isotope, and daily urine samples collected for 15 days postdosing. We urge that further research is needed to evaluate the impact of various thickening agents on the bioavailability of water from the developing gut and in cases of gut pathology and recommend our methodology.
Springer Science+Business Media, LLC 2009
The exact mechanisms by which non-starch polysaccharides increase stool output are unknown. In the present study the hypothesis that the site of fermentation and short-chain fatty acid (SCFA) accumulation is related to the action of non-starch polysaccharides (NSP) on stool output was tested. The basal diet (45 g NSP/kg) of forty-three male Wistar rats was supplemented with 50 g/kg of either guar, karaya, tragacanth, gellan, xanthan or ispaghula for 28d. A further twenty-three rats were maintained on the basal diet for the same time period. Faeces were then collected over 2 d and caecal contents obtained post-mortem. Caecal and faecal wet and dry weights and SCFA were measured. Each supplement had a different effect on the caecal and faecal contents but they appeared to fall into three groups when compared with the basal diet. In group 1, guar gum affected only caecal SCFA. It had no effect on stool output or faecal SCFA. In group 2, karaya increased caecal SCFA and tragacanth, karaya and xanthan increased faecal SCFA and faecal water. In group 3, ispaghula and geUan had no consistent effect on caecal or faecal SCFA concentrations but increased total faecal SCFA output and increased faecal wet and dry weight. Although the knowledge that SCFA are rapidly absorbed in the large intestine has led us to believe that they play no role in determining faecal output, these results suggest that in some cases where NSP are slowly fermented, and increase faecal SCFA, the role of the SCFA may need to be reassessed.
British Journal of Nutrition (1995), 73, 773-781 773
Background: Studies amongst older people with acute dysphagic stroke requiring thickened fluids have assessed fluid intakes from combinations of beverage, food, enteral and parenteral sources, but not all sources simultaneously. The present study aimed to comprehensively assess total water intake from food, beverages, enteral and parenteral sources amongst dysphagic adult in-patients receiving thickened fluids.
Methods: Patients requiring thickened fluid following dysphagia diagnosis were recruited consecutively from a tertiary teaching hospital’s medical and neurosurgical wards. Fluid intake from food and beverages was assessed by wastage, direct observation and quantified from enteral and parenteral sources through clinical medical records.
Results: No patients achieved their calculated fluid requirements unless enteral or parenteral fluids were received. The mean daily fluid intake from food was greater than from beverages whether receiving diet alone (food: 807 ± 363 mL, food and beverages: 370 ± 179 mL; P < 0.001) or diet with enteral or parenteral fluid support (food: 455 ± 408 mL, food and beverages: 263 ± 232 mL; P < 0.001). Greater daily fluid intakes occurred when receiving enteral and parenteral fluid in addition to oral dietary intake, irrespective of age group, whether assistance was required, diagnosis and whether stage 3 or stage 2 thickened fluids were required (P < 0.05). After enteral and parenteral sources, food provided the most important contribution to daily fluid intakes.
Conclusions: The greatest contribution to oral fluid intake was from food, not beverages. Designing menus and food services that promote and encourage the enjoyment of fluid dense foods, in contrast to thickened beverages, may present an important way to improve fluid intakes of those with dysphagia. Supplemental enteral or parenteral fluid may be necessary to achieve minimum calculated fluid requirements.
Introduction: Long-term care (LTC) residents, especially the orally fed with dysphagia, are prone to dehydration. The clinical consequences of dehydration are critical. The validity of the common laboratory parameters of hydration status is far from being absolute, especially so in the elderly. However, combinations of these indices are more reliable.
Objective: Assessment of hydration status among elderly LTC residents with oropharyngeal dysphagia.
Methods: A total of 28 orally fed patients with grade-2 feeding difficulties on the functional outcome swallowing scale (FOSS) and 67 naso-gastric tube (NGT)-fed LTC residents entered the study. The common laboratory, serum and urinary tests were used as indices of hydration status. The results were considered as indicative of dehydration and used as ‘markers of dehydration’, if they were above the accepted normal values.
Results: The mean number of dehydration markers was significantly higher in the FOSS-2 group (3.8 8 1.3 vs. 2 8 1.4, p = 0.000). About 75% of these FOSS-2 patients had 6 4 dehydration markers versus 18% of the NGT-fed group (p = 0.000). A low urine output ( ! 800 ml/day) was significantly more common in the FOSS-2 group (39 vs. 12%, p = 0.002). Above normal values of blood urea nitrogen (BUN), BUN/serum creatinine ratio (BUN/SC r) , urine/serum osmolality ratio (U/S Osm) , and urine osmolality U Osm , were significantly more frequent in the dehydration-prone FOSS-2 group. This combination of 4 indices was present in 65% of low urine output patients. In contrast, it was present in only 36% of the higher urine output patients (p = 0.01). Patients with a ‘normal’ daily urine output ( 1 800 ml/day) also had a significant number (2 8 1.5) of positive indices of dehydration.
Conclusions: Dehydration was found to be common among orally fed FOSS-2 LTC patients. Surprisingly, probable dehydration, although of a mild degree, was not a rarity among NGT-fed patients either. The combination of 4 parameters, BUN, BUN/S Cr , U/S Osm and U Osm , offers reasonable reliability to be used as an indication of dehydration status in daily clinical practice.
A high incidence of oropharyngeal dysphagia (OD) in acute-care settings has been reported; however, no data on its management are found in the literature. Here we report the experience with rehabilitative management of OD in a large Italian hospital. The characteristics of inpatients with OD during 2004 have been studied prospectively. For each patient, demographic data, the department referring the patient, the disease causing OD, and the presence of a communication disorder were registered. The swallowing level at the beginning and at the end of rehabilitation were recorded. Of the 35,590 inpatients admitted to San Giovanni Battista Hospital of Turin during 2004, 222 of them were referred for the assessment and rehabilitation of OD. The inpatients with OD came from different departments and mainly had a neurologic disease. In 110 patients a communication disorder was present. The swallowing impairment was moderate to severe at the moment of referral, while on average patients were able to eat by mouth after swallowing therapy. Dysphagia rehabilitation in an acute care setting is requested from different departments because of its prevalence and severity; skilled specialists are needed for early assessment and the best management.
Springer Science+Business Media, LLC 2007
Texture-modified diets are commonly prescribed for patients with dysphagia; it is therefore important to demonstrate that clinicians form accurate impressions of the rheological (flow) properties of the items that they recommend for their clients. We explored the correlation between objective rheological measurement and clinicians’ subjective impressions of liquid consistency, rated on the bases of product labeling and sampling. Ten liquids, ranging from thin through nectar-thick and honey-thick to spoon-thick consistencies, were selected for study. Rheological analysis was conducted using a Carri-Med CSL Controlled Stress Rheometer. Fifty speech- language pathologists ranked the liquids in order of perceived viscosity, based on their interpretation of the product packaging and label. Product nomenclature proved insufficient to accurately represent the consistency class to which each liquid belonged. A second group of 16 speech-language pathologists rated the perceived relative viscosity and density of nectar-thick and honey-thick juice items in blinded two-point discrimination tests of stirring-resistance, oral manipulation, and vessel weight. Physical sampling of these two products enabled clinicians to reliably perceive relative viscosity and density differences between the nectar- and honey-thick items.
Background: In dysphagia care, thickening powders are widely added to drinks to slow their flow speed by increasing their viscosity. Current practice relies on subjective evaluation of viscosity using verbal descriptors. Several brands of thickener are available, with differences in constituent ingredients and instructions for use. Some thickened fluids have previously been shown to exhibit time-varying non-Newtonian flow behaviour, which may complicate attempts at subjective viscosity judgement.
Aims: The aims were to quantify the apparent viscosity over time produced by thickeners having a range of constituent ingredients, and to relate the results to clinical practice.
Methods & Procedures:A comparative evaluation of currently available thickener products, including two which have recently been reformulated, was performed. Their subjective compliance to the National Descriptors standards was assessed, and their apparent viscosity was measured using a rheometer at shear rates representative of situations from slow tipping in a beaker (0.1 s–1) to a fast swallow (100 s–1). Testing was performed repeatedly up to 3 h from mixing.
Outcomes & Results: When mixed with water, it was found that most products compared well with subjective National Descriptors at three thickness levels. The fluids were all highly non Newtonian; their apparent viscosity was strongly dependent on the rate of testing, typically decreasing by a factor of almost 100 as shear rate increased. All fluids showed some change in viscosity with time from mixing; this varied between products from 234% to 37% in the tests. This magnitude was less than the difference between thickness levels specified by the National Descriptors.
Conclusions & Implications: The apparent viscosity of thickened fluids depends strongly on the shear rate at which it is examined. This inherent behaviour is likely to hinder subjective evaluation of viscosity. If quantitative measures of viscosity are required (for example, for standardization purposes), they must therefore be qualified with information of the test conditions.
This study compared the viscosity (thickness) of five different liquids thickened to nectar- or honey-like consistencies with a variety of thickening products. Samples were prepared using manufacturer guidelines and viscosity was measured at the recommended time to thicken (standard) and also after 10 and 30 min. Centipoise (cP) measurements of the samples were compared across products and within product lines for each level of thickness at all three time periods. Statistical analysis showed that the viscosity of a nectar- or honey-like liquid was highly dependent on the type of thickening product and the time it was allowed to thicken. Variability in viscosity measurements also was noted within a product line for thickening various liquids. Results are discussed in relation to the National Dysphagia Diet guidelines for nectar- and honey-like consistencies.
06 September 2011
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